The UK's next prime minister will face high calibre Brexit rebels

Key government ministers could fight any attempt to seek a no-deal Brexit

Finance minister Philip Hammond is among the key Conservative opposers of a no-deal Brexit. AFP

While the UK's governing Conservative Party focuses on who will succeed Theresa May as prime minister, some senior figures are already thinking about how they’re going to make life difficult for her successor.

If the bookmakers’ favourite Boris Johnson wins the contest, he’s going to find a very high calibre of internal opponent to deal with. Chancellor of the Exchequer Philip Hammond has indicated he’ll fight any attempt to seek a no-deal Brexit, and Mr May has dropped heavy hints that she could join him.

The most outspoken potential troublemaker is Justice Secretary David Gauke. The 47-year-old has until now built a career on being studiously loyal to his leaders and a willingness to defend the government in tight moments.

But now he’s getting ready to fight and, in an interview published Thursday, made clear he’ll resist any attempt to leave the European Union without an agreement.

“It would knock back our economy very significantly,” he told The House magazine. “I want us to leave with a deal. It’s a view that quite a lot of ministers hold and will continue to argue that case.”

He didn’t criticise Cabinet colleagues who are supporting Mr Johnson, but warned the front-runner’s strategy of allowing different audiences to believe different things about his plans is storing up trouble: “In the end, somebody is going to feel very disappointed,” he said.

It’s unusual for senior ministers to attack their new leader even before he’s arrived, but it reflects a problem Mr Johnson faces. Having undermined Mrs May when he was in her Cabinet, and then spent the last year attacking her from the backbenches, he will find plenty of people - perhaps including Mrs May herself - ready to pay him back in kind.